PCS-A027
PCS_a027_chgInsufficientCooling
Also written as PCS_A027 / PCS A027 / PCS_a027_chgInsufficientCooling / pcs_a027_chginsufficientcooling
Why does the exact Tesla alert ID matter?
Record the exact alert ID, including underscores, suffixes, and companion alerts. Tesla alerts that look similar can point to different modules, timestamps, and service procedures.
What does PCS-A027 mean?
Tesla alert code in the Power Conversion System (PCS) module. PCS does not detect coolant flowing Charger detects that coolant flow is insufficient Charge cable is removed or inserted or battery management system issues clear fault request Charging derated due to too large of a voltage drop between starting charge and during charge info from manualPCS_A053 Charger detects greater than 12% input voltage drop after ramping power Charger input voltage exceeds alert clear threshold Reduced AC charge rate, possibly due to bad wiring external to vehicle PCS detects the HV bus impedance is lower than the expected value DCDC converter detects low impedance on HV bus when precharging (short circuit or capacitance too high) Charging derated due to high measured grid impedance (impedance detection algorithmn) PCS experienced a watchdog reset
Original Description
PCS does not detect coolant flowing Charger detects that coolant flow is insufficient Charge cable is removed or inserted or battery management system issues clear fault request Charging derated due to too large of a voltage drop between starting charge and during charge info from manualPCS_A053 Charger detects greater than 12% input voltage drop after ramping power Charger input voltage exceeds alert clear threshold Reduced AC charge rate, possibly due to bad wiring external to vehicle PCS detects the HV bus impedance is lower than the expected value DCDC converter detects low impedance on HV bus when precharging (short circuit or capacitance too high) Charging derated due to high measured grid impedance (impedance detection algorithmn) PCS experienced a watchdog reset
Affected Tesla Models
What You May Notice
- Power Conversion System alert: PCS does not detect coolant flowing Charger detects that coolant flow is insufficient Charge cable is removed or inserte
- DC-DC converter issue may affect 12V system (lights, accessories)
- Alert shown in the Tesla app
How to Diagnose and Resolve
- 1 Reboot the vehicle
- 2 Check if 12V accessories (lights, door handles) are behaving normally
- 3 Schedule a Tesla Service appointment for PCS inspection
Severity Notes
PCS-A027 is an Alert in the Power Conversion System system. Confirm the vehicle screen and Tesla app show no driving or charging restrictions, and schedule service if the alert returns.